The phrase "accounted for" means to explain, justify, or consider someone or something in a particular context. It implies that you have taken into account all relevant factors or elements when evaluating a situation or making a report. For example, if a teacher says all students were accounted for during attendance, it means that the teacher confirmed the presence or absence of each student.
The term "accounted for" comes from the verb "account," which originates from the Old French word "acont," meaning "to count or reckon." The phrase itself suggests a process of calculation or consideration, especially in determining the whereabouts or status of something.